Rock bit



Patented May 27, 1952 UNITED STATES PATENT'OFFICE- ROCK BIT Normand E.Dufilho, Longview, Tex.

Application April 21, 1948, Serial No. 22,350

3 Claims. (01. 255-71) This invention relates to drill bits of the typeused for rock and hard formations wherein the cutting action isaccomplished through crushing or chipping, and in particular a rockdrill having a rotary cutter head positioned to rotate about an axis atan acute angle to the axis of the drill body whereby the teeth of thebit head are set down in rotation order as with a walking effect andwithout circular slippage.

The purpose of this invention is to provide an improved drill bit fordriling wells for oil, gas, water, and the like wherein the teeth of arotary cutter head advance step by step whereby cutting is accomplishedby a crushing and chipping action.

The usual bits for drilling wells and the like are designed to operateon various mechanical principles such as the drag bit which cuts orremoves the material or formation in its path by scraping with one ormore blades, and the rock bit which was intended primarily forformations too hard to be cut by the drag bit and which consists oftoothed cones or wheels which attack the formation with a crushingaction, but because of the hard service to which these bits are put theuseful life thereof is relatively short. With this thought in mind thisinvention contemplates a drill bit having a rotating body with a cutterhead rotatably mounted thereon and positioned at a slight angle to thebody wherein roller bearings are provided between the cutter head andbody to take the thrust and a centrally disposed passage is providedthrough the body providing a drilling mud passage for carrying 01fcuttings which flow upward outside of the bit.

The object of this invention is, therefore, to provide an improved drillbit for drilling rock and other hard formations with a crushing andchipping action.

Another object of the invention is to provide an improved drill bithaving a rotary cutter head in which roller bearings are used to takethe thrust.

Another object of the invention is to provide a drill bit which operateswith a step by step actlon providing a rotary crushing or chippingeffect as it operates.

A further object of the invention is to provide an improved rock drillhaving a rotating body with a cutter head rotatably carried thereonwhich is of a simple and economical construction With these and otherobjects and advantages in view the invention consists of the new anduseful combination. construction, and arrangement of parts ashereinafter more fully described,

set forth in the claims appended hereto and disclosed in theaccompanying drawings forming part hereof, wherein:

Figure 1 is a view showing a side elevation of the drill head with partbroken away showing a vertical section through the cutter head thereofand illustrating the drill in an opening.

Figure 2 is a view looking upward toward the under surface of the cutterhead showing the teeth, and taken on line 22 of Figure 1.

Figure 3 is a cross section through the drill body taken on line 3-3 ofFigure 1.

Figure 4 is a section between the drill body and cutterhead taken online 44 of Figure 1.

Referring now to the drawings wherein like reference characters denotecorresponding parts the improved rock drill of this invention includes adrill body l0 and a cutter head I l which is rotatably mounted an onangularly disposed spindle l2 of the body.

The drill body is cylindrical and a tapering threaded shank I3 isprovided at the upper end by which it may be attached to a drill rod.The intermediate portion of the drill body is provided withsubstantially semi-circular recesses M in whichrollers 15 with pins [6extending from the ends thereof are positioned. These rollers contactthe wall surfaces of the well and take the lateral thrust holding thedrill centered in the well.

The spindle l2 extends from an inclined surface l'l, to which it isperpendicular, and the axis of the spindle intersects the axis of thedrill body at the point I8, the axis of the spindle and cutter headbeing at an acute angle to the axis ofthe drill body. The spindle I2 isprovided with an annular recess l9 which registers l with a similarrecess 2!! in an opening 2| in the cutter head, and balls are positionedin the recesses, as indicated by the numeral 22. The end of the spindleis provided with a collar 23 having an annular recess 24 therein inwhich a sealing ring 25, extending from a similar recess 26 in thecutter head, is positioned to insulate the bearing areas from dirt,grit, and the like. Radially disposed roller bearings 21 are positionedaround the collar 23 which bear against the end of the spindle and innersurface 28 of the cutter head. A gasket 29 is also provided between theend of the body or surface I! and the inner end of the cutter head tofurther seal and protect the bearings.

The outer surface 30 of the cutter head II is positioned thereon, and asillustrated in Figure l, the angle between the axis of the cutter headand drill body is determined in relation to the cutting face of thecutter head so that the teeth on one side of the center of the cutterhead will be positioned perpendicular to the axis of the drill body, andas the drill body is rotated the teeth will advance, step by step,cutting the rock with a chipping and crushing action.

The center of thecutter head ll is provided with an opening 32 whichcommunicates with a centrally disposed opening 33 in the drill bodyproviding a drilling mud passage for carrying 01f cuttings which flowupward outside of the bit.

It will be understood that modifications .may be made in the design andarrangement of the parts without departing from the spirit of theinvention.

What is claimed is:

.1. .In a rotary rock drill bit, the combination which comprises acylindricaldrill body having an inclined surface on the lower end with aspindle extended from the said inclined surface and with the spindlepositioned whereby the axis thereof "is perpendicular to the saidinclined surface andintersects the longitudinal axis of the drill bodyat a point spaced from the said inclined :surface, the lower end of saidspindle having a. conical surface and the lower side of said conicalsurface being perpendicular to the axis of said drill body, and a drillheadhaving conical shaped inner and outer surfaces journaled on thespindle and positioned with the conical shaped inner surface coactingwith the conical shaped end surface of the spindle and having concentricrows of radially disposed cutting teeth extended outwardly from the saidouter conical shaped surface thereof, said drill body having bearingsurfaces on the outer surface thereof and the periphery of said drillhead being aligned with the said bearing surfaces of the'drill body.

2. In a rotary rock drill bit, the combination which comprises-acylindrical drill body having an inclined surface on the lower end witha spindle extended from the said inclined surface and with the spindlepositioned whereby the axis thereof is perpendicular to the saidinclined surface and intersects the longitudinal axis of the drill bodyat a point spaced from the said inclined surface, the lower end of saidspindle having a conical surface and the lower side of said conicalsurface being perpendicular to the axis of said drill body, and a-drillhead having conical shaped inner and outer surfaces journaled on thespindle and positioned with the conical shaped inner :surfacecoactingwith the conical shaped end surface of the spindle and having concentricrows of radially disposed cutting teeth extended outwardly from the saidouter conical shaped surface thereof, said teeth being staggered andhaving radially disposed open mud escape channels between the teeth,said drill body anddrill headhaving a vertically 4 positioned centrallydisposed passage extended from the face of the drill head upwardlythrough the drill body providing a mud passage, said drill head havingan inner end surface positioned perpendicular to the axis of the saidspindle upon which the drill head is positioned and extended to contactthe said inclined surface on the lower end of the drill body, said endsurface of the drill head and inclined surface of thedrill body coactingwith the conical shaped surface at the end of the-spindle to provideincreased bearing surfaces for withstanding the excessive load resultingfrom operation of the drill bit.

3. In a rotary rock drill bit, the combination which comprises acylindrical drill body having an inclined surface on the lower end witha spindle extended from the said inclined surface and with the spindlepositioned whereby the axis thereof is perpendicular to the saidinclined surface and intersects the longitudinal axis of the drill bodyat a point spaced from the said inclined surface, thelower end of saidspindle having a conical surface and the lower side of saidconicalsurface being perpendicular to the axis of said drill body, a drill headhaving conical shaped inner and outer surfaces journaled on the spindleand positioned with the conical shaped inner surface coacting with theconical shaped end surface of the spindle and having concentric rows ofradially disposed cutting teeth extended outwardly from the said outerconical shaped surface thereof, said teeth being staggered and havingradially disposed open mud escape channels between the teeth. radiallydisposed roller bearings positioned between the inner conical shapedsurface of the head and end surface of the spindle, and spacedlongitudinally positioned bearing rollers .journaled inthe outerperipheral surface of the drill body and positioned with the outersurfaces thereof parallel to the outer surface-and axis of the saiddrill body.

NORMAND E. DUFILHO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

